function getRem(prem, pwidth) {
	var html = document.getElementsByTagName("html")[0];
	var oWidth = $(window).width() || document.body.clientWidth || document.documentElement.clientWidth;
	html.style.fontSize = oWidth / pwidth * prem + "px";
	return oWidth / pwidth * prem;
}
function getBeforeDate(n) {//当前为0，前一天为-1，后一天为1  n表示几天的
	var date = new Date();
	var year, month, day;
	date.setDate(date.getDate() + n);
	year = date.getFullYear();
	month = date.getMonth() + 1;
	day = date.getDate();
	s = ( month < 10 ? ( '0' + month ) : month ) + '月' + ( day < 10 ? ( '0' + day ) : day)+'日';
	return s;
}




